System for starting internal combustion engines or the like by means of electric motors



July 4, 1939. C N 2,164,909

SYSTEM FOR STARTING INTERNAL COMBUSTION ENGINES OR THE LIKE BY MEANS OF ELECTRIC MOTORS Filed Aug. 26, 1957 IN\ E,NTOR= ALBERT GACHON b fl/wwwfl ATTORNEYS F'atentecl July 4, 1939 UNITED STATES PATENT other Albert Grachon, Lyon, France, assignor :to Societe .deParis .& du Rhone, Lyon, :France, a corporation :of France Application August 26,

1937, Serial .No. 161,080

In France -September '10, 1936 4 Claims.

This invention relates to improvements in systems for starting internal combustion engines or the like by means of electric motors.

One -of the main difficulties encountered in starting an internal combustion engine by means of an electric motor, especially in connection with automobiles, is'the engagement of the teeth of the starter pinion-with the toothed Wheel connected to the engine. In the known systems in which, upon excitation of the starter, the pinion moves by inertia upon a helical inclination located upon the shaft of the starter in order to age with the toothed wheel, it is frequently found that despite careful design of the shape of the teeth the pinion wedges against the teeth of the wheel and it is' necessary to stop the mechanism in order to reset the device. In the systems known as positive control systems in which the engagement of the pinion is controlled by the operator, by means for example of a system of rods, two teeth oftencome opposite to each other and it is not possible to effect the engagement of the teeth without moving One of the toothed wheels by external means.

Difiiculties in connection with the relative positions of the gear wheels are overcome by the present invention.

The invention will be clearly explained with reference to the accompanyingdrawing in which 30 Figures 1 and 2 are diagrammatic sectional views of two embodiments thereof, similar reference characters relating to corresponding parts in the two figures.

In Figure 1, a starter I bears a pinion 2 which is arranged in constant engagement with an annular toothed member 3. The toothed member 3 is arranged to be movable in an axial direction and is free to rotate about the fixed part 1 of the engine casing 5; a resetting system not shown on the drawing in Fig. 1 for clarity, but which may comprise a system of springs which appear at l9 in Fig. 2, maintains the toothed member 3 in a position in which it is normally out of contact with the flywheel 8, without interfering With the freedom of movement thereof about the fixed part 1.

In order to start the engine the coil 6 is connected to a source of current, whereupon the toothed member 3 adheres by magnetic attraction to the flywheel 8 which is integral with the shaft 4 of the engine. Current is then supplied to the starter and the internal combustion engine is driven. Once the starting is effected it is then only necessary to isolate the source of current from the starter I andthe coil 6 by any conventional means.

In Figure 1,, the energy of the starter is applied to a tooth-ed member which may be made integral with the engine by engagement with a member fixed -on the shaft of the engine such for example as the flywheel, but it may also be arranged, for example, to engage the reducing gear with some other rotating member fixed on the shaft.

The diagram of Figure 1 is only given by way of example clearly to explain the principle of the invention which concerns the introduction of an electromagnetic coupling between the reducing system actuated by the starter and the shaft of the engine to be started. Further features of the present invention are concerned with useful constructional details, which facilitate the construction of the device or ensure the perfect operation thereof under the particularly difficult conditions encountered when the engine to be started is subject to back-firing.

As shown in Figure 1, it is advantageous to support the member 3 by a fixed part I of the engine to be started in such a manner that after starting any supplementary friction is avoided. Nevertheless, in View of the comparatively large diameter of this member'it would in general be expensive to mount it upon a roller or ball device (or the like) which would permit free rotation thereof. This difliculty is overcome by arranging the various members in the manner shown in Figure 2, which is given by way of example only. According to such an arrangement, the toothed member 3, which is actuated by the starting motor I through the pinion 2, bears upon a fixed rim 9 of the casing 5 of the engine to be started. The position of the member 3 upon the rim 9 is maintained by a suitable return device represented in Figure 2 by a movable friction member l8 under the influence of a spring I9. The magnetising coil 6 is arranged to be energised through a brush connected to the terminal [1 and arranged to slide over a metallic conductor inserted in an insulated ring l6, and through the engine casing. When the coil 6 is energised, the toothed member 3 is completely disconnected from the supporting rim 9 and bears against the flywheel 8 upon which it is centered by means of the conical formation l2. A bearing device is thus obviated since during the starting process the movable member 3 no longer engages the fixed rim 9; to facilitate such detachment the exterior of the rim 9 may be of conical formation. Various modifications of the present invention are possible in particular in respect of the device for the return of the member 3, that indicated in Figure 2 being given by Way of example only.

An important advantage of the present invention is in the application thereof to the starting of an engine which is subjected to back-firing, producing rotation in the contrary direction to the normal rotation, because beyond a certain limit, the magnetic clutch will let go and slip; with the known starting devices extensive damage may be produced under such conditions, the mechanism being subjected to excessive stresses. The member 3 and flywheel 8 virtually form what may be termed a magnetic couple. Hence, by suitably regulating the magnetic adhesion between the member 3 and the flywheel 8 (Figure an eificient couple-limiting device is produced, which limits the strain that can be transmitted to the engine to a safe maximum, beyond which the member 3 and flywheel 8 will no longer mutually adhere but will slip.

What I claim as my invention and desire to secure by Letters Patent of the United States is:

1. In a starting system for an internal combustion engine located in a casing and provided with a revolving member on its shaft, said system including an electric starting motor, a reducing system having one member integral with the motor and another member which forms a rim of a gear disposed between the casing and the revolving member, and electromagnetic clutch means between said gear rim and said revolving member, the combination of means for suspending on the casing the gear rim disposed between said casing and the revolving member, means for axially displacing the rim toward the revolving member, means for controlling such axial displacement by the electromagnetic clutch means, elastic means for returning the rim to the casing when said clutch is not energized, and separate means for centering said rim on the surface of the revolving member.

2. A system according to claim 1, in which the centering means include engaging means between part of the surface of the rim and part of the surface of the revolving member.

3. A system according to claim 1, in which the rim and revolving members constitute cooperating members and the centering means include a male cone on one of the cooperating members and a corresponding conical cup in the surface of the other of said cooperating members.

4. A system according to claim 1, in which the centering means include a male cone on the surface of the revolving member and a corresponding conical cup in the rim of the gear.

ALBERT GACHON. 

